Recently, an increased awareness has arisen about the potential detrimental impact of certain consumer products on the environment. A chemical in certain products which appears to cause great harm to the environment is chlorofluorocarbon (CFC). This chemical is used in many types of void fill packing materials made of polystyrene. Void fill packing material is necessary to provide cushion or protection of a packaged product during delivery and mailing. Apart from the disadvantages of polystyrene possessing CFCs, polystyrene also does not decompose rapidly thereby adding to the material entering land fills and waste dumps.
Polystyrene void fill material is often called polystyrene "peanuts" and comes in a variety of shapes and sizes. Polystyrene "peanuts" are lightweight and are easily positioned around a product in its package through the use of a suspended hopper assembly having a lower spout for pouring the "peanuts" into their proper placement. Polystyrene "peanuts" work well in this hopper assembly due to their good flow rate through the lower spout. That is, these peanuts flow through the spout in a substantially unobstructed manner.
Many alternative void fill materials are available for product packaging. For instance, shredded wood, cornstarch, shredded paper and popcorn are a few alternative void fill packaging materials. Many of these packaging materials are not lightweight and do not flow through a spout in a hopper assembly for placement around a product in its package. As such, these void fill materials must be placed around a package by hand. Such hand packing of heavyweight void fill material leads to injuries such as Carpal Tunnel Syndrome. Other packing materials, such as cornstarch and popcorn, attract insects. Cornstarch, shredded paper and popcorn also tend to deposit natural oils, ink or other residue upon the products which they surround. Most of these void fill materials also possess the disadvantage of degradation in cushioning ability at a higher rate than polystyrene "peanuts" thereby making it impractical as a void fill material. Further, the high cost of most of these packing materials make their use prohibitive.
A known method of recycling corrugated cardboard provides an inexpensive and environmentally safe alternative to void fill packing materials. The best known packaging material implemented in this fashion is "quadropack" which is recycled shredded corrugated cardboard fan-folded into strips. This product, however, does not dispense easily through a hopper assembly because of negative "flow" characteristics through a lower spout.
Rotary die cutters, however, could produce an effective void fill material made from recycled cardboard or hardboard sheet papers products with better flow characteristics. Void fill material made from recycled paper products also avoid the disadvantages inherent in previously used void fill materials. This void fill material is environmentally safe and avoids the addition of unrecycled material to waste dumps. Further, this void fill material is lightweight, does not attract insects and does not leave any residue on the packaged product.
The use of rotary die cutters is well known for preparing cardboard and paper products for commercial applications. Most rotary die cutters include a dual cylinder design wherein one cylinder is the cutter cylinder and the other cylinder is the anvil cylinder. During operation, an unworked piece of cardboard is placed between the cutter cylinder and the anvil cylinder such that the anvil cylinder supports the cardboard while the blades on the outside of the cutter cylinder work upon the cardboard. The use of the rotary die is herein explained using cardboard as the work piece, but it is understood that any type of hard or firm sheet material may be worked upon by this type of rotary die cutter for use as void fill material.
Rotary die cutters work upon the cardboard to cut, score or crease the cardboard in the manner desired. The cutter cylinder usually possess different types of blades to perform each operation. Cutting blades are long, sharp blades for cutting the cardboard. Scoring blades are long, serrated blades for scoring the cardboard so the cardboard may be easily folded upon the scored line. And, creasing blades are shorter, blunt blades used for making shallow creases or impressions in the cardboard or paper products thereby bending or folding the cardboard at the crease. Together, these blades shape and configure the cardboard workpiece to suit the particular commercial application desired.
The cardboard usually originates from a supply stack and is conveyed to the rotary die cutter. Once conveyed to the rotary die cutter, the cardboard is fed between the cutter and anvil cylinders. One or both cylinders are rotated in order to continuously feed the cardboard product between the cylinders. The rotation of the cylinders moves the cardboard therethrough and onward to another conveying means. Ultimately, the final workpiece is transferred to an output destination. The rotation of the cylinders, as well as the conveying means and feeding process, are accomplished by means well-known in the art.
After the cardboard product is worked upon by the rotary die cutter, workpieces and waste material are usually created. Portions of the cardboard not to be used in the final commercial product are considered waste material. Sometimes the entire piece of cardboard fed between the cylinders is used as the final commercial product without the production of any waste material. Both the waste material and the workpiece, however, must be ejected from the die cutting cylinder in order to provide a clean cutting surface when the cutter cylinder rotates around again to work upon the next surface of a cardboard piece conveyed to the rotary cutter device.
Ejector or ejection systems are often used to assure the ejection of the workpieces and any waste material so as to avoid any obstruction of the cutting surface of the rotary die cutter. Known ejection systems include mechanical and magnetic types of ejection systems. Mechanical ejectors include foam rubber and other spring-type ejectors placed within the cutting areas. These mechanical types of ejectors expand after the actual cutting operation is completed to eject the cut workpiece. Magnetic ejectors include magnetic material which is attracted and moved at a certain position in the cutting cycle to force the workpiece or waste material away from the cutter cylinder.
These mechanical and magnetic ejection systems possess numerous disadvantages when implemented in systems producing a large number of small workpieces. For instance, it is impractical in many instances to place mechanical or magnetic ejectors in each of the separate cutting elements when the number of cut workpieces is very large. Additionally, the foam rubber spring-type ejectors cannot expand sufficiently from the cutter cylinder when the cut workpiece is small.
Pressurized gas has also been used to force workpieces away from the cutter blades or activate plungers on the exterior of the cutter cylinder to force the workpiece away from the cylinder by the force of the plunger. Many cutter cylinders possess coverings on the outer surface of the cutter cylinder, however, which obstruct the pressurized airflow used to eject cut workpieces in a gas pressurized ejection system. When a large number of small workpieces are cut, the pressurized airflow must minimize the number of obstructions so that sufficient airflow forces each cut workpiece away from the cutter cylinder. Thus, simple pressurized air systems possess substantial disadvantages when implemented on a cutter cylinder possessing obstacles to the airflow on the surface of the cutter cylinder. Further, plungers are expensive and impractical when the number of cut workpieces is very large.
Most cutter cylinders are fabricated by placing a plywood cover over a base mount cylinder. A single long cutting blade is bent into the configuration desired to cut the sheet material. This bent blade is hammered into the plywood outer cover thereby allowing the cutting blades to extend in a secured fashion radially on the cutting cylinder. The cutting cylinder is then ready to work upon the cardboard.
The placement of the cutting blades in the plywood cover of the base mount cylinder requires a tremendous amount of skill and experience to accomplish correctly. Thus, the placement and replacement of cutter blades is a very difficult process for an unexperienced worker. Another substantial disadvantage with this technique is the need to replace an entire blade portion of this cutter cylinder in the event the blade is damaged or defective. Replacement of the entire blade is often an expensive and time-consuming proposition, and is necessary even if only a small portion of the blade is damaged or defective. Further, gas pressurized ejection systems will not work effectively in this conventional cutter cylinder due to the obstructions imposed by the plywood covering.